How to Easily Calculate Your Insulin-to-Carb Ratio & Basal-Insulin Requirements


Determining your insulin requirements may seem difficult, but it is actually quite easy.

Understanding these calculations empowers you to make informed decisions about your insulin doses, enhancing your overall health and well-being.

This article will teach you how to easily calculate your:

  1. Insulin-to-carb ratio, and
  2. Basal-insulin requirement.

How to Calculate Your Insulin-to-Carb Ratio

Your insulin-to-carb ratio is how much insulin you need to cover a given amount of carbohydrate.

Determining your insulin-to-carb ratio is quite individual. Your doctor will therefore need to determine your insulin-to-carb ratio.

  • Let’s say, however, that your doctor tells you to take 1 unit of rapid-acting insulin for every 15 grams of carbohydrate you eat.
  • Let’s also say that the meal you are going to eat has 44 grams of carbohydrate.
    • Divide 44 carbohydrate grams by 15
      • You get 2.9.
        • This means you’ll need 2.9 units of rapid-acting insulin to cover your meal.

It’s that easy … Use the calculator below to practice.

Your Doctor Recommended 1 Unit to Carbs Total:

Total Carbs for the meal:

Your Results


How to Calculate Your Basal-Insulin Requirement

Basal insulins are long-acting insulins used to maintain stable blood-sugar levels.

To calculate your basal-insulin requirement, you must first find your weight in kilograms.

  • Assume you weigh 190 pounds.
  • Divide 190 by 2.2
    • You get 86.36.
      • That’s your weight in kilograms.

The formula for calculating basal-insulin requirements has an upper range of 0.4 units of basal insulin per kilogram of body weight and a lower range of 0.2 units of basal insulin per kilogram of body weight.

Assume—for the purposes of this hypothetical scenario—that your physician has determined that your basal-insulin demand is 0.3 units per kilogram of body weight.

  • Multiply 86.36 (your weight in kilograms) by 0.3
    • You get 25.91
      • This is the number of units you need for your daily basal-insulin requirement.

Again, use the calculator below to practice.

Just like your insulin-to-carb ratio, talk to your doctor to further establish the appropriate insulin dose for you.

Enter Your Weight

Weight measurement: or
Your Weight:

Your Results


This content was made possible by Lilly, a Founding Partner of Beyond Type 1.

Beyond Type 1 maintains editorial control over its content.

WRITTEN BY Daniel Trecroci, POSTED 06/28/24, UPDATED 06/28/24

Dan has written about diabetes for more than 20 years. He was one of Diabetes Health's first recruits, and throughout his 10 + years as Managing Editor he wrote/published thousands of articles and helped establish Diabetes Health as the premiere resource for people with diabetes. He later became the Content Manager for OneTouchGold—Johnson & Johnson/LifeScan’s official digital publication for its metering-technology customers. Under his leadership, OneTouchGold received the Web Marketing Association’s award for “Best Health & Wellness" web site. Dan has also written for the Diabetes Research Institute, dLife, diaTribe, Healthline, CareDx, Pendulum Therapeutics, and Hero Bread.